Unless your friend has traveled to Prague and done it himself, I wouldn't risk it especially in the middle of the tourist season. It is possible to get a room however (we've done it in the south of France in the summer) but you won't be able to get it for more than one night; hotels will gladly sell you rooms at half the price (or more) if they are not sold by 6 p.m.

Having said this, Prague is not as affordable as it was once. Hotel prices in the city center are shocking. And beware of cab drivers; even the mayor of Prague, who posed as an Italian tourist in 2005, was scammed by an unsuspecting cabbie. Also beware of pickpocketers.

BTW, in my opinion, 9 days in Prague are too long. And if you're going to Prague for the bars and club scenes, the action has moved to Bratislava.

Send me a PM if you need more info about PRG.